Help me choose an M1 oil for my fleet, please.

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Time for everyone's favorite game.....PICK......MY......OIL!!!!

I'm trying to finalize my oil selection to unify the oil stash to support my 2018 Forester 2.5L and my 2015 Chrysler 3.6L. I'm trying to decide between 5W20, 5W30, 10W30 and maybe 0W40. The reason I'm limiting it to Mobil 1 is because I can get the 6qt cases at costco on sale regularly and the Mobil 1 rebates.

I'd like to keep these cars until rust prevents me from keeping them anymore. Of course my main concerns are engine and timing chain wear. I have pretty much ruled out 0W20 because both are a bit noisy on startup with this oil and I'm not convinced 0w20 is best for the timing chain.

As for cold start info, the cars are always kept in the garage overnight. We see winter temperatures dip to 0F but on average, I would say my cars actually have to cold start at 0F or lower about 2-5 times a year. A more consistent cold start temperature in winter would be about 10F.

I thought I would just do 0W40 but all the recent talk of it being loaded with VIIs and how they may not be so great for timing chains has me a bit gunshy on that one.

Anyways, please feel free to recommend something. Thanks.
 
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Originally Posted by oil_film_movies
M1 AFE 0w30 will be perfect for both.


I thought about that one but unfortunately Costco does not carry that oil. No idea why.
 
I say 20w50 and substitute one quart with Lucas oil stabilizer then top it off with a dollop with lithium grease for good measure, thicker is better right! JK, I would run 5w30 year round in both, what ever synthetic is on sale, 5000-7500 OCI probably be fine too.
 
Dang. Timing chains. Probably 16 feet of them.
I say 0w40 FS. Its temporary shear ratio is pretty respectable for a 0w40, and the HTHS is just a notch above minimum.
And it has more ZDDP than any of the 20's and 30's.
 
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Originally Posted by badtlc
Originally Posted by oil_film_movies
M1 AFE 0w30 will be perfect for both.


I thought about that one but unfortunately Costco does not carry that oil. No idea why.

Because it's not generally one recommended any more by manufacturers in an API gasoline specification. I do remember when GM was recommending it for cold climates only, as in never seeing over 50ºF. I thought that the European spec cars with 0W-30 were basically with specific standards, such as BMW.
 
Originally Posted by buster
How long do you plan on running the oil? I would consider regular Mobil 1 5w30 or AFE 0w30 if you're following the OEM recommended drain interval.

https://www.mobil.com/English-US/Passenger-Vehicle-Lube/pds/GLXXMobil-1-5W30



The Chrysler 3.6L runs about 9,500 miles before the OLM goes off. I just run it 10k OCIs and call it a day.

The Forester will likely get 10k OCIs as well. The FB25 is super easy on oil based on the UOAs and no signs of fuel issues in the oil.
 
Originally Posted by A_Harman
Dang. Timing chains. Probably 16 feet of them.
I say 0w40 FS. Its temporary shear ratio is pretty respectable for a 0w40, and the HTHS is just a notch above minimum.
And it has more ZDDP than any of the 20's and 30's.

+1
 
The Mobil 1 0w40 FS has a SA of 1.34 and a good slug of calcium. I'm not sure that would be on the top of my list for those engines. If you go the 0w40 route, I'd use the ESP.
 
You really cannot go wrong with good old Mobil 1 5W-30. It's a high quality product available at a good price.

The 0W-40 is a more viscous oil that has a fantastic pour point and very high viscosity index. Many people use it with good results.
 
Originally Posted by y_p_w
Originally Posted by oil_film_movies
M1 AFE 0w30 will be perfect for both.
Because it's not generally one recommended any more by manufacturers in an API gasoline specification. I do remember when GM was recommending it for cold climates only, as in never seeing over 50ºF.
GM recommends 0w30 (on those engines where a 5w30 is also recommended) in any area of the country where it can get to -20F. M1 AFE 0w30 dexos1 is the main choice for areas where it gets cold, yet GM knows the weather can change suddenly, and get above 50F easily with 0w30 still in the sump. Nowhere in my '18 GM Owner's Manual does it say I can't use 0w30 dexos1 oil when its over 50F outside. So your statement is just not true. Use M1 AFE 0w30 freely wherever 5w30 dexos1 is specified, as its HTHS is right for that application. (And, Amsoil fans, use their dexos1-capable 0w30 SS instead of 5w30 SS whenever you want, all temperatures too.)
Originally Posted by y_p_w
I thought that the European spec cars with 0W-30 were basically with specific standards, such as BMW.
As GM has dexos1 specs, yes BMW & others have specs which include 0w30. Everybody has specs, and often 0w30 is a choice within that spec.
 
Last edited:
Originally Posted by oil_film_movies
Originally Posted by y_p_w
Originally Posted by oil_film_movies
M1 AFE 0w30 will be perfect for both.
Because it's not generally one recommended any more by manufacturers in an API gasoline specification. I do remember when GM was recommending it for cold climates only, as in never seeing over 50ºF.
GM recommends 0w30 (on those engines where a 5w30 is also recommended) in any area of the country where it can get to -20F. M1 AFE 0w30 dexos1 is the main choice for areas where it gets cold, yet GM knows the weather can change suddenly, and get above 50F easily with 0w30 still in the sump. Nowhere in my '18 GM Owner's Manual does it say I can't use 0w30 dexos1 oil when its over 50F outside. So your statement is just not true. Use M1 AFE 0w30 freely wherever 5w30 dexos1 is specified, as its HTHS is right for that application. (And, Amsoil fans, use their dexos1-capable 0w30 SS instead of 5w30 SS whenever you want, all temperatures too.)
Originally Posted by y_p_w
I thought that the European spec cars with 0W-30 were basically with specific standards, such as BMW.
As GM has dexos1 specs, yes BMW & others have specs which include 0w30. Everybody has specs, and often 0w30 is a choice within that spec.

I haven't kept up with GM requirements. I do remember when they were the first to recommend 0W-30 and it was only recommended for cold temps. This was after my dad's Regal with the 3800 Series II where 5W-30 was only recommended for cold climates, although they recommended a "synthetic 5W-30" for really cold temps.

Again - haven't kept up on GM requirements.
 
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